Impact of sarcopenia on time to achievement of target peak VO2 during cardiac rehabilitation.

BACKGROUND

Sarcopenia is prevalent among patients with cardiovascular disease and is associated with reduced exercise capacity. However, its impact on the rate of improvement in exercise tolerance during cardiac rehabilitation (CR) remains unclear. This study investigated whether sarcopenia influences the timing and speed of achieving target peak oxygen uptake (peak VO2) during CR.

METHODS

This retrospective observational study included consecutive patients aged 50 years or older with cardiovascular disease who participated in a standardized outpatient CR program once weekly at a single center. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2025 criteria. The primary outcome was achievement of ≥80% of predicted peak VO2, as recommended by the 2021 Japanese Circulation Society guidelines. Time to achievement was analyzed using Kaplan-Meier curves and the log-rank test. Cox proportional hazards models were used to assess the association between sarcopenia and achievement of the target after adjustment for clinically relevant covariates, including age, sex, and baseline peak VO2.

RESULTS

A total of 144 patients were analyzed, of whom 71 (49.3%) had sarcopenia at baseline. During a median follow-up of 134 days, 136 patients achieved ≥80% of predicted peak VO2. Kaplan-Meier analysis demonstrated that patients with sarcopenia had a significantly slower rate of achievement compared with those without sarcopenia (log-rank p = 0.001). Approximately 40% of patients with sarcopenia failed to achieve the target even after 150 days, corresponding to the maximum reimbursable period for CR under the Japanese health insurance system. Sarcopenia remained independently associated with delayed achievement of the target in multivariable Cox analysis.

CONCLUSIONS

Sarcopenia is associated with a slower rate of improvement in exercise capacity during cardiac rehabilitation, independent of baseline exercise capacity. Early identification of sarcopenia may help optimize rehabilitation strategies and goal setting in patients undergoing CR.